The quantitative determination of analytes in body fluids is of great importance in the diagnoses and maintenance of certain physiological abnormalities. For example, glucose, lactate, cholesterol and bilirubin should be monitored in certain individuals. In particular, it is important that individuals who are diabetics frequently check the glucose level in their body fluids to regulate the glucose intake in their diets. The results of such tests can be used to determine what, if any, insulin or other medication needs to be administered. In one type of blood-glucose testing system, test sensors are used to test a sample of blood.
A test sensor contains biosensing or reagent material that reacts with, for example, blood glucose. One type of a test sensor is an electrochemical test sensor. An electrochemical test sensor is a multilayer test sensor which includes a base or substrate, a lid and a reagent system that reacts with the analyte of interest. The electrochemical test sensors include at least two electrodes in the form of an electrode pattern. A potential is applied across these electrodes and a current is measured at the working electrode. The current is indicative of the concentration of the analyte. It is also contemplated that other types of test sensors may be used including optical test sensors. In optical test sensors, the reagent system and the analyte are reacted to produce a chromatic reaction, which causes the sample to change color. The degree of color change is indicative of the analyte concentration in the body fluid.
The reagent system that is used with the test sensors is sensitive to moisture and other contaminants. Thus, test sensors are often sealed in containers or packaging to prevent moisture or contaminants from affecting the reagent. Current forms of test sensor packaging include drum and blister packs, which are both large in size but hold only a relatively small number of test sensors. Such packaging requires additional attention and effort from the manufacturer. It also may make it more difficult to automatically install the test sensor into a testing device or meter.
Manufacturers and users would benefit from being able to eliminate the sealed containers and bulky packaging and still have any amount of test sensors that a user may desire to carry with the testing device or in a bag and/or container. Therefore, it would be desirable to have a test sensor that does not require sealed packaging, but which still prevents or inhibits moisture and contaminants from affecting the reagent system.